Comparison of fermentative capacities of lactobacilli in single and mixed culture in industrial media

Abstract

This paper is concerned with comparing the fermentative capacity of single and mixed cultures of lactobacilli on batch lactic acid fermentation. The fermentation characteristics of five strains of lactic acid bacteria, Lactobacillus delbrueckii subsp. lactis (ATCC 12315), Lactobacillus casei (NRRL-B1445), L. delbrueckii (NRRL-B445), Lactobacillus helveticus (NRRL-B1937), and L. casei (NRRL-B1922), were compared in de Man–Rogosa–Sharpe (MRS) media. Cell growth, glucose utilization, lactic acid synthesis, and free amino acid production were the main parameters studied. Strain B1445 was found to be the excellent lactic acid bacterium for the production of lactic acid with a high yield. Production of lactic acid from corn steep liquors by fermentation was studied using strain B1445 and mixed type of five lactobacilli. Even though nitrogen source consumption in mixed culture was lower than that of single culture, the cell density and lactic acid production were better in mixed culture than single culture. These results suggest that mixed culturing of lactobacilli may be more effective than single culturing of Lactobacillus for improving lactic acid production.